Grammarly

Grammarly is an AI writing assistant that checks and improves your writing wherever you type — email, documents, browsers, chat apps and more. It started as a grammar and spelling checker and now covers clarity, tone, full-sentence rewrites, AI text generation, plagiarism checking and AI-content detection. Grammarly says it is used by more than 40 million people and 50,000 organisations, and it is now part of Superhuman, a suite that also includes Superhuman Go, Coda and Superhuman Mail.

Its advantage over chatbots is where it works. Rather than copying text into a separate AI tool, Grammarly gives suggestions directly in the apps and websites you already use. You keep writing; it underlines problems and offers fixes in place.

Grammarly has also added Docs, an AI writing surface with specialised agents: a Citation Finder that finds sources supporting or contradicting your claims and formats citations, Reader Reactions that predicts how a chosen reader will respond, an AI Grader that scores assignments against a rubric, a Humanizer, a Paraphraser, an AI Detector and a Plagiarism Checker.

How Grammarly works

A typical workflow is:

1. Install the browser extension, desktop app or mobile keyboard, or open Grammarly Docs.
2. Write as normal — in Gmail, Google Docs, Word, Slack, LinkedIn or almost anywhere.
3. Accept or dismiss underlined suggestions for correctness, clarity and tone.
4. Use AI prompts to draft, rewrite or shorten text when you need a starting point.
5. Before you send or submit, run Citation Finder, Plagiarism Checker or AI Detector in Docs.
6. On Pro teams, apply style guides, brand tones and snippets so everyone writes consistently.

Key capabilities

Correctness — Spelling, grammar and punctuation suggestions as you type, on every plan.

Tone detection and adjustment — See how your writing comes across on Free; adjust it with a click on Pro.

Full-sentence rewrites — Rewrite unclear or wordy sentences in one click (Pro).

Fluency — Suggestions to help non-native speakers write natural English (Pro).

Generative AI prompts — Draft, rewrite, summarise or reply with AI: 100 prompts a month on Free, 2,000 per member on Pro, unlimited on Enterprise.

Plagiarism checker and AI detector — Check work for unoriginal or AI-generated text (Pro).

Citation Finder — Finds publicly available sources that support or contradict your points and generates citations in APA, MLA and other styles.

Reader Reactions — Predicts the key takeaways, open questions and potential confusion for a chosen reader, such as a manager or professor.

AI Grader — Feedback and an estimated grade against your rubric; full use on Pro, one free scan a day on Free.

Humanizer and Paraphraser — Make AI-assisted text sound natural, or adapt writing to a new audience and tone.

Team tools (Pro) — Style guides, brand tones, knowledge share, snippets and usage analytics for up to 149 members.

Grammarly plans explained

Free is genuinely usable for as long as you like. It covers spelling, grammar and punctuation, shows your writing tone, includes 100 AI prompts a month and one AI Grader scan a day. Full-sentence rewrites and tone adjustment are not included.

Pro is billed per member: $30 a month, $60 a quarter, or $144 a year — the headline $12 a month is the annual plan, paid upfront. It adds full-sentence rewrites, tone adjustment, fluency suggestions, unlimited personalised suggestions, plagiarism and AI detection, 2,000 AI prompts per member a month and all app actions, plus team features such as style guides, brand tones, snippets and analytics. Pro has a 7-day free trial with no payment due on the day and an email reminder two days before it ends. One Pro plan can cover up to 149 seats, billed as a single payment.

Enterprise is sold by quote through Superhuman Go and adds unlimited prompts, dedicated support, BYOK encryption, custom roles and permissions, data loss prevention and cost-centre visibility.

Premium is still available, but only through the App Store and Google Play. It includes the core writing features and 1,000 AI prompts a month, without Pro's team tools. Grammarly does not sell gift subscriptions, lifetime plans or one-time purchases.

Who Grammarly is for

Professionals — clear, correctly toned email and documents without switching apps.

Students — Citation Finder, AI Grader and plagiarism checks for essays and assignments.

Non-native English speakers — fluency suggestions for more natural phrasing.

Small teams — shared style guides and brand tones so everyone writes consistently.

Getting the most out of Grammarly

Don't accept every suggestion — use it to catch mistakes and unclear sentences, then keep the phrasing that sounds like you.

Set your goals (audience, formality, intent) so tone suggestions match what you're writing.

Run Citation Finder and Plagiarism Checker before submitting or publishing anything that relies on sources.

If you write every day, choose annual billing — month-to-month Pro costs well over twice as much across a year.